rework console to support simple cannon and raw mode

so3/devices/console.c

@@ -16,19 +16,77 @@
  *
  */
 
+#include <termios.h>
 #include <device/serial.h>
 
+/* Default termios flags that will be used by the console. */
+static termios_t termios = {
+	.c_iflag = INLCR,
+	.c_lflag = ECHO | ICANON,
+};
+
+static int console_write(int fd, const void *buffer, int count);
+
+static char console_get_next_c(void)
+{
+	char c = serial_getc();
+
+	/* Convert CR to LF if required */
+	if (termios.c_iflag & INLCR) {
+		if (c == '\r')
+			c = '\n';
+	}
+
+	return c;
+}
+
+static void icanon_handle_char(int fd, char c, char *buf, size_t *total)
+{
+	/* Backspace handle */
+	if (c == 127) {
+		if (*total != 0) {
+			/* Delete last char from console and buffer */
+			buf[*total] = '\0';
+			(*total)--;
+
+			if (termios.c_lflag & ECHO)
+				console_write(fd, "\b \b", 3);
+		}
+
+		return;
+	}
+
+	/* Generic handle */
+	buf[*total] = c;
+	(*total)++;
+
+	if (termios.c_lflag & ECHO)
+		console_write(fd, &c, 1);
+}
+
 /* Used to read from a serial (uart) console. We report only one byte when the byte is ready. */
-static int console_getc(int gfd, void *buffer, int count)
+static int console_getc(int fd, void *buffer, int count)
 {
-	/* Read one byte from the UART console */
-	*((uint8_t *) buffer) = serial_getc();
+	char c;
+	char *c_buf = (char *) buffer;
+	size_t total = 0;
 
-	return 1;
+	if (termios.c_lflag & ICANON) {
+		do {
+			/* Read and handle next byte  */
+			c = console_get_next_c();
+			icanon_handle_char(fd, c, c_buf, &total);
+		} while (c != '\n' && total < count);
+	} else {
+		*c_buf = console_get_next_c();
+		total = 1;
+	}
+
+	return total;
 }
 
 /* Send out to the serial console. */
-static int console_write(int gfd, const void *buffer, int count)
+static int console_write(int fd, const void *buffer, int count)
 {
 	int ret;
 
@@ -43,6 +101,21 @@ static int console_ioctl(int fd, unsigned long cmd, unsigned long args)
 	int rc;
 
 	switch (cmd) {
+	case TCGETS:
+		*(struct termios *) args = termios;
+		rc = 0;
+		break;
+
+	case TCSETS:
+	case TCSETSW:
+	case TCSETSF:
+		/* We should normally wait for all output to be trasmitted
+		   and flush input depending on the IOCTL. But we will assumed
+		   this will already by ok for now. */
+		termios = *(struct termios *) args;
+		rc = 0;
+		break;
+
 	case TIOCGWINSZ:
 		rc = serial_gwinsize((struct winsize *) args);
 		break;

so3/include/termios.h

@@ -0,0 +1,195 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+/* Copied from Linux:
+ *  - include/uapi/asm-generic/ioctls.h
+ *  - include/uapi/asm-generic/termbits.h
+ *  - include/uapi/asm-generic/termbits-common.h
+ */
+
+#ifndef TERMIOS_H
+#define TERMIOS_H
+
+/* clang-format off */
+
+/* IOCTL for termios management */
+#define TCGETS		0x5401
+#define TCSETS		0x5402
+#define TCSETSW		0x5403
+#define TCSETSF		0x5404
+
+#define NCCS 19
+
+typedef unsigned char cc_t;
+typedef unsigned int speed_t;
+typedef unsigned int tcflag_t;
+
+typedef struct termios {
+	tcflag_t c_iflag;
+	tcflag_t c_oflag;
+	tcflag_t c_cflag;
+	tcflag_t c_lflag;
+	cc_t c_line;
+	cc_t c_cc[NCCS];
+	speed_t __c_ispeed;
+	speed_t __c_ospeed;
+} termios_t;
+
+/* c_cc characters */
+#define VINTR		 0
+#define VQUIT		 1
+#define VERASE		 2
+#define VKILL		 3
+#define VEOF		 4
+#define VTIME		 5
+#define VMIN		 6
+#define VSWTC		 7
+#define VSTART		 8
+#define VSTOP		 9
+#define VSUSP		10
+#define VEOL		11
+#define VREPRINT	12
+#define VDISCARD	13
+#define VWERASE		14
+#define VLNEXT		15
+#define VEOL2		16
+
+/* c_iflag bits */
+#define IGNBRK	0x001			/* Ignore break condition */
+#define BRKINT	0x002			/* Signal interrupt on break */
+#define IGNPAR	0x004			/* Ignore characters with parity errors */
+#define PARMRK	0x008			/* Mark parity and framing errors */
+#define INPCK	0x010			/* Enable input parity check */
+#define ISTRIP	0x020			/* Strip 8th bit off characters */
+#define INLCR	0x040			/* Map NL to CR on input */
+#define IGNCR	0x080			/* Ignore CR */
+#define ICRNL	0x100			/* Map CR to NL on input */
+#define IXANY	0x800			/* Any character will restart after stop */
+#define IUCLC	0x0200
+#define IXON	0x0400
+#define IXOFF	0x1000
+#define IMAXBEL	0x2000
+#define IUTF8	0x4000
+
+/* c_oflag bits */
+#define OPOST	0x01			/* Perform output processing */
+#define OCRNL	0x08
+#define ONOCR	0x10
+#define ONLRET	0x20
+#define OFILL	0x40
+#define OFDEL	0x80
+#define OLCUC	0x00002
+#define ONLCR	0x00004
+#define NLDLY	0x00100
+#define   NL0	0x00000
+#define   NL1	0x00100
+#define CRDLY	0x00600
+#define   CR0	0x00000
+#define   CR1	0x00200
+#define   CR2	0x00400
+#define   CR3	0x00600
+#define TABDLY	0x01800
+#define   TAB0	0x00000
+#define   TAB1	0x00800
+#define   TAB2	0x01000
+#define   TAB3	0x01800
+#define   XTABS	0x01800
+#define BSDLY	0x02000
+#define   BS0	0x00000
+#define   BS1	0x02000
+#define VTDLY	0x04000
+#define   VT0	0x00000
+#define   VT1	0x04000
+#define FFDLY	0x08000
+#define   FF0	0x00000
+#define   FF1	0x08000
+
+/* c_cflag bit meaning */
+/* Common CBAUD rates */
+#define     B0		0x00000000	/* hang up */
+#define    B50		0x00000001
+#define    B75		0x00000002
+#define   B110		0x00000003
+#define   B134		0x00000004
+#define   B150		0x00000005
+#define   B200		0x00000006
+#define   B300		0x00000007
+#define   B600		0x00000008
+#define  B1200		0x00000009
+#define  B1800		0x0000000a
+#define  B2400		0x0000000b
+#define  B4800		0x0000000c
+#define  B9600		0x0000000d
+#define B19200		0x0000000e
+#define B38400		0x0000000f
+#define EXTA		B19200
+#define EXTB		B38400
+
+#define CBAUD		0x0000100f
+#define CSIZE		0x00000030
+#define   CS5		0x00000000
+#define   CS6		0x00000010
+#define   CS7		0x00000020
+#define   CS8		0x00000030
+#define CSTOPB		0x00000040
+#define CREAD		0x00000080
+#define PARENB		0x00000100
+#define PARODD		0x00000200
+#define HUPCL		0x00000400
+#define CLOCAL		0x00000800
+#define CBAUDEX		0x00001000
+#define BOTHER		0x00001000
+#define     B57600	0x00001001
+#define    B115200	0x00001002
+#define    B230400	0x00001003
+#define    B460800	0x00001004
+#define    B500000	0x00001005
+#define    B576000	0x00001006
+#define    B921600	0x00001007
+#define   B1000000	0x00001008
+#define   B1152000	0x00001009
+#define   B1500000	0x0000100a
+#define   B2000000	0x0000100b
+#define   B2500000	0x0000100c
+#define   B3000000	0x0000100d
+#define   B3500000	0x0000100e
+#define   B4000000	0x0000100f
+#define CIBAUD		0x100f0000	/* input baud rate */
+
+#define ADDRB		0x20000000	/* address bit */
+#define CMSPAR		0x40000000	/* mark or space (stick) parity */
+#define CRTSCTS		0x80000000	/* flow control */
+
+#define IBSHIFT		16		/* Shift from CBAUD to CIBAUD */
+
+/* c_lflag bits */
+#define ISIG	0x00001
+#define ICANON	0x00002
+#define XCASE	0x00004
+#define ECHO	0x00008
+#define ECHOE	0x00010
+#define ECHOK	0x00020
+#define ECHONL	0x00040
+#define NOFLSH	0x00080
+#define TOSTOP	0x00100
+#define ECHOCTL	0x00200
+#define ECHOPRT	0x00400
+#define ECHOKE	0x00800
+#define FLUSHO	0x01000
+#define PENDIN	0x04000
+#define IEXTEN	0x08000
+#define EXTPROC	0x10000
+
+/* tcflow() ACTION argument and TCXONC use these */
+#define TCOOFF		0		/* Suspend output */
+#define TCOON		1		/* Restart suspended output */
+#define TCIOFF		2		/* Send a STOP character */
+#define TCION		3		/* Send a START character */
+
+/* tcflush() QUEUE_SELECTOR argument and TCFLSH use these */
+#define TCIFLUSH	0		/* Discard data received but not yet read */
+#define TCOFLUSH	1		/* Discard data written but not yet sent */
+#define TCIOFLUSH	2		/* Discard all pending data */
+
+/* clang-format on */
+
+#endif // TERMIOS_H

usr/src/more.c

@@ -21,6 +21,8 @@
 
 #include <fcntl.h>
 
+#include <termios.h>
+#include <signal.h>
 #include <unistd.h>
 #include <syscall.h>
 #include <stdio.h>
@@ -32,9 +34,19 @@
 
 char buf[BUFSIZE];
 struct winsize wsz;
+struct termios old_term;
+
+/* Handler for sigint to restore console flags. */
+void sigint_handler(int sig)
+{
+	tcsetattr(STDERR_FILENO, TCSANOW, &old_term);
+	exit(0);
+}
 
 int main(int argc, char **argv)
 {
+	struct termios raw_term;
+	struct sigaction sa = {};
 	int quit = 0;
 	int fd = STDIN_FILENO, nb_bytes, line_max, columns_max;
 	int cpt_columns = -1, cpt_line = 0;
@@ -53,8 +65,20 @@ int main(int argc, char **argv)
 			return 2;
 		}
 	}
+
+	/* Save old console mode */
+	tcgetattr(STDERR_FILENO, &old_term);
+
+	/* Set SIGINT handler to restore the terminal mode correctly */
+	sa.sa_handler = sigint_handler;
+	sigaction(SIGINT, &sa, NULL);
+
+	/* Set console mode to raw */
+	cfmakeraw(&raw_term);
+	tcsetattr(STDERR_FILENO, TCSANOW, &raw_term);
+
 	/* Get number of lines and columns */
-	err = ioctl(STDOUT_FILENO, TIOCGWINSZ, &wsz);
+	err = ioctl(STDERR_FILENO, TIOCGWINSZ, &wsz);
 	if (err != 0) {
 		printf("Errno: %d\n  ioctl error %d\n", errno, err);
 		return 3;
@@ -97,7 +121,16 @@ int main(int argc, char **argv)
 				printf("\n--MORE--");
 				fflush(stdout);
 
-				key = getc(stderr);
+				/* Read next char. Don't use getc as it requires
+				   a FILE* and this will result in no actual read
+				   on stderr. stdin isn't available as it can be
+				   an input pipe. */
+				err = read(STDERR_FILENO, &key, 1);
+				if (err != 1) {
+					quit = 1;
+					break;
+				}
+
 				if ((key == 'q') || (key == 'Q')) {
 					quit = 1;
 					break;
@@ -113,5 +146,7 @@ int main(int argc, char **argv)
 	}
 	putchar('\n');
 
+	tcsetattr(STDERR_FILENO, TCSANOW, &old_term);
+
 	return 0;
 }